TitleIdentification of proteins of the infectious apparatus of Encephalitozoon cuniculi
NameGhosh, Kaya (author), Bonder, Edward (chair), Cali, Ann (internal member), Kafkewitz, David (internal member), Altan-Bonnet, Nihal (internal member), Weiss, Louis (outside member), Chan, John (outside member), Rutgers University, Graduate School - Newark,
DescriptionThe microsporidia are a diverse phylum of obligate intracellular parasitic protists that infect all major animal groups and have been recognized as emerging human pathogens for which few chemotherapeutic options currently exist. These organisms infect every tissue and organ system, causing significant pathology especially in immune-compromised populations. The microsporidian spore employs a unique infection strategy in which its contents are virtually injected into a host cell via the polar tube, an organelle that lies coiled within the resting spore but erupts with a force sufficient to pierce the plasma membrane of its host cell. It appears that this process is driven by a dramatic osmotic swelling within the spore just prior to germination, which is resisted by the spore wall until the moment of polar filament eruption. Neither the means by which this rapid influx of water across the hydrophobic cell membrane might be supported, nor the molecular structural basis for the elasticity of the polar tube or the tensile strength of the spore wall is well understood. However, the recent sequencing of the genome of human-pathogenic species Encephalitozoon cuniculi has enabled the adoption of genomic and proteomic approaches to address these problems. In the first part of this project, an aquaporin-like gene from this organism (EcAQP) was cloned and the protein subjected to standard functional tests in a heterologous Xenopus oocyte swelling assay. Increased water-permeability and localization of EcAQP to the plasma membrane of transfected oocytes demonstrated the functionality of this gene, suggesting a mechanism for water flux in germinating spores. The second part of this project employed a shotgun-proteomic strategy to identify novel structural components of the microsporidian infectious apparatus. Mass spectrometry of insoluble fractions of spore lysate identified over fifty candidate proteins, many of which were immunolocalized in situ. As a result, novel components of the mitosome, the developing spore wall, and a heretofore unrecognized filamentous network within the lumen of the parasitophorous vacuole were putatively identified. Thus the work described herein generates insights regarding the biochemical events and molecular structural components involved in the infectious process of these unique intracellular pathogens.
NoteIncludes bibliographical references (p. 150-164)
Noteby Kaya Ghosh
CollectionGraduate School - Newark Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.